Earthquakes

What is an Earthquake?

• Earthquakes are caused by the movement of rock deep within the Earth’s crust.

Energy is Released

• Sudden movements that release significant amounts of energy in the form of primary and secondary seismic waves.

Focus and Epicentre

• The place where the rock movement occurs is called the focus.

• The place directly above on the Earth’s surface is called the epicentre.

Measuring Earthquakes

Richter Scale• Measures the amount of energy released from

the earthquake (magnitude) over 6 is considered a major EQ

Mercalli Scale

• measures the impact on humans (1-12)

• Devastation after Earthquake in Haiti 2010

Christchurch

• Chistchurch Earthquake 22, Feb 2011

• Magnitude 6.3

• Mercalli 10

• http://www.christchurchquakemap.co.nz/

• http://www.youtube.com/watch?v=BfcWraeZvcw

Over to you

Use your and the textbook (p97-98) to answer the following Questions.

• 1. What types of earthquakes occur in Australia?

• 2. Outline some of the impacts of earthquakes.

• 3. a) What factors would affect the rating an earthquake receives on the Mercalli Scale ? (e.g the location of the epicentre)

b) Outline what can be done to minimise these effects.

• 4. Complete “Applying and Analysing” Question 1 on page 101